2001 4WD won't engage - clunking noise front end

When I try to engage 4WD, there is a clunking noise from the left front end, and it feels as though it's not even engaging. When I turn the switch back to 2WD, it will still clunk unlessI stop and go back and forth a couple times. Have been told it may be a broken front axle? Any help/advice would be highly appreciated.

well you were told right. you got abroken cv shaft. if its the left side turn your wheel to right. look for your shaft,if its clunking like you said it should move pretty freely.not to hard to do. just remember to get 2 codder pins 1 for cv, 1 for tie rod end,and the hub socket before you leave the auto store. get a goooooooood breaker bar, my impact couldnt get my s-10 hub nut off. and that was overPSIing thegun to 130psi w/126gallon tank.but she was a WOODSBEATER.pb it to hell, depending on rims take center cap out, if socket fits through the rim GREAT. its much easier to break free. if nottake rim off get a long crowbar and lay one end onthe ground then wrap a shirt around other end andweave it under a lug and then over a lug. "shirts to try and prevent lugs getting f****d up. when ya broke it free. take off brakes. take off tie rod end.undo bottom shock bolt. undo cv bolts, near diff. separate from diff. and wiggle her out. redo everthing. id rate it as a 12pack event . this is what i had to do onthe last time i did a cv joint. probibly not the correct nor safeist way. but i got her done.